CN111295173A

CN111295173A - Silicate glass and dental product

Info

Publication number: CN111295173A
Application number: CN201880071988.7A
Authority: CN
Inventors: 山田和广; 榊原肇男; 坂清子
Original assignee: Kuraray Noritake Dental Inc
Current assignee: Kuraray Noritake Dental Inc
Priority date: 2017-11-07
Filing date: 2018-11-06
Publication date: 2020-06-16
Also published as: US11472729B2; EP3708139A1; US20210179481A1; JP7223706B2; EP3708139B1; KR20200078503A; EP3708139A4; WO2019093336A1; JPWO2019093336A1

Abstract

The invention provides a silicate glass which can inhibit the change of the color tone of zirconia as a base material even though the silicate glass is calcined with a zirconia green body, and a dental product using the silicate glass. The present invention relates to: silicate glass comprising 65.0 to 90.0mol% of SiO₂4.0 to 15.0mol% of Al₂O₃1.0 to 10.0mol% of K₂O, 0.1 to 7.0mol% of Na₂O and 0.01 to 15.0mol% of CaO, and substantially not containing B₂O₃，{(Al₂O₃Is given in mole number of (3)/(RO + R)₂Total mole number of O) } of 0.70 or more, the metal represented by ROR of the oxide represents a metal element of group 2 or group 12 of the periodic table, R₂R of the metal oxide represented by O represents a metal element of group 1 of the periodic table; a composite comprising the silicate glass and a substrate comprising a ceramic: a sintered body obtained by calcining the composite; and a dental product comprising the sintered body.

Description

Silicate glass and dental product

Technical Field

The present invention relates to a silicate glass and a dental product having the silicate glass.

Background

Conventionally, metals have been used as dental products (for example, prostheses such as crowns, braces, and dentures). However, metals have a disadvantage of lacking aesthetic properties, and there are cases where allergy is caused by elution of metals. Therefore, in order to solve the problems associated with the use of metals, ceramic materials such as alumina (alumina) and zirconia (zirconia) are used in dental products instead of metals. In particular, zirconia is excellent in appearance and strength, and in particular, demand has been increasing with the recent reduction in price.

In addition, in order to improve the aesthetic appearance in the oral cavity, it is necessary to make the appearance of the dental product similar to that of natural teeth. However, it is difficult to reproduce the same appearance as that of natural teeth, particularly transparency, gloss (luster), and color tone, by zirconia (sintered body) itself. Therefore, a crown is used which does not expose zirconia but calcines silicate glass called ceramic material on the exposed surface of the frame formed of zirconia so as to intend to reproduce the same appearance as that of a natural tooth. Such a dental product is obtained by calcining zirconia and further calcining silicate glass as a dental ceramic material. Such dental products are known as ceramic calcined Zirconia crowns (PFZ: Porcelain Fused to Zirconia).

In general, a zirconia sintered body itself does not have transparency and luster like natural teeth. Therefore, in order to make PFZ have the same appearance as that of natural teeth, it is desirable that the appearance of PFZ as viewed from the dental ceramic material side has the same color tone and gloss as those of natural teeth in a state where the dental ceramic material is fired on a frame of a zirconia sintered body. As such a dental ceramic material, for example, a coating material for dental prostheses disclosed in patent document 1 is proposed.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 5-194130.

Disclosure of Invention

Problems to be solved by the invention

In recent years, it has been desired to install dental products in the oral cavity in 1 (1 day) medical treatment called a one-day treatment. Therefore, focusing on the requirements for simplicity in the steps and the desire for as short a production time as possible, the present inventors have studied simplification of the steps and shortening of the production time by applying or building a dental ceramic material on a base material comprising a non-sintered body and calcining the base material and the dental ceramic material at the same time in a method for producing a dental product comprising the base material comprising the sintered body.

On the other hand, patent document 1 discloses an invention of a coating material for dental prostheses which is coated on a dental prosthesis including a zirconia material, and reports that the surface of a sintered body such as metallic zirconium is coated with the coating material for dental prostheses and then calcined. The coating material for dental prostheses is characterized by comprising glass as a constituent component, each of which contains in the following ranges by weight%: 62-75% of SiO₂3-15% of Al₂O₃4 to 10% of Li₂O, 4-15% of Na₂O, 5.5-15% ZrO₂And/or HfO₂。

However, the coating material for dental prostheses described in patent document 1 has a calcination temperature of 950 ℃ or lower due to the composition of its constituent components, and in order to simplify the steps and shorten the production time, as the above-mentioned production method studied by the present inventors, when the coating material for dental prostheses described in patent document 1 is applied to a zirconia green body and calcined at the same time, discoloration (color difference) occurs in the zirconia sintered body as a base material, and it is estimated that PFZ exhibiting the same color tone and gloss as those of natural teeth cannot be obtained.

In view of the above, an object of the present invention is to provide a silicate glass capable of suppressing a change in the color tone of zirconia as a base material even if calcined simultaneously with a zirconia green body. Further, the present invention has an object to provide a composite comprising the above silicate glass and a base material, a sintered body thereof, and a dental product thereof.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found that a silicate glass contains SiO as a constituent component₂、Al₂O₃、K₂O、Na₂The content of each of O and CaO is set to a predetermined range, and thereby, the change in color tone of the zirconia sintered body when the zirconia sintered body is calcined by coating a silicate glass thereon and the color tone when the zirconia green body and the silicate glass are simultaneously calcined can be reduced.

That is, the present invention relates to the following inventions.

[1] A silicate glass comprising:

65.0 to 90.0mol% SiO₂、

4.0 to 15.0mol% of Al₂O₃、

1.0 to 10.0mol% of K₂O、

0.1 to 7.0mol% of Na₂O, and

0.01 to 15.0mol% of CaO,

substantially free of B₂O₃，

{(Al₂O₃Is given in mole number of (3)/(RO + R)₂Total mole number of O) } is 0.70 or more, R of the metal oxide represented by RO represents a metal element of group 2 or group 12 of the periodic table, R represents₂R of the metal oxide represented by O represents a metal element of group 1 of the periodic TableAnd (4) element.

[2] The silicate glass according to the aforementioned [1], which comprises:

69.0 to 89.0mol% SiO₂、

5.0 to 13.0mol% of Al₂O₃、

3.0 to 9.0mol% of K₂O、

1.0 to 4.0mol% of Na₂O, and

0.05 to 13.0mol% of CaO,

substantially free of B₂O₃，

{(Al₂O₃Is given in mole number of (3)/(RO + R)₂Total mole number of O) } is 0.70 or more.

[3] The silicate glass according to the above [1] or [2], which contains substantially no ZnO.

[4] The silicate glass according to any one of the above [1] to [3], which contains substantially no MgO, BaO, and SrO.

[5] The silicate glass according to any one of the above [1] to [4], wherein the suitable calcination temperature is 1100 ℃ or more.

[6]According to the above [1]]~[5]The silicate glass according to any one of claims, wherein the glass composition is in accordance with ISO 6872: 2015 to a thermal expansion coefficient of 11.0X 10^-6K-1The following.

[7] The silicate glass according to any one of the above [1] to [6], further comprising at least 1 selected from a pigment and an opacifying agent.

[8] A composite comprising the silicate glass according to any one of the above [1] to [7] and a substrate comprising a ceramic.

[9] The composite body according to the aforementioned [8], wherein the ceramic is a zirconia ceramic.

[10] A sintered body of the composite body according to the above [8] or [9 ].

[11] A dental product comprising the sintered body of the above [10 ].

ADVANTAGEOUS EFFECTS OF INVENTION

The silicate glass of the present invention can suppress a change in color tone of a zirconia sintered body as a base material even when the zirconia green body and the silicate glass are simultaneously calcined at a zirconia calcination temperature. That is, since the zirconia green body and the silicate glass can be used for firing at the same time, a dental product including the sintered body can be obtained in a simple procedure and in a short time.

Detailed Description

The silicate glass of the present invention contains 65.0 to 90.0mol% of SiO₂4.0 to 15.0mol% of Al₂O₃1.0 to 10.0mol% of K₂O, 0.1 to 7.0mol% of Na₂O and 0.01 to 15.0mol% of CaO, and substantially not containing B₂O₃。

In the present specification, the expression of each component constituting silicate glass (for example, "SiO₂"etc.) are the cases where the respective elements such as metals (e.g., Si, etc.) contained in the silicate glass are regarded as being present in the form of oxides. That is, for example, even if a certain metal element and another metal element form a composite, the metal elements are considered to form an oxide. The content of each component contained in the silicate glass is, as described above, the content of the oxide when it is considered that each element forms an oxide.

The silicate glass of the present invention contains SiO as a constituent₂。SiO₂The content of (b) is 65.0mol% or more, preferably 69.0mol% or more, and more preferably 69.8mol% or more based on the total number of moles of the components constituting the silicate glass. In SiO₂When the content of (B) is less than 65.0mol%, the suitable calcination temperature of the resultant silicate glass is too low. Furthermore, SiO₂The content of (b) is 90.0mol% or less, preferably 89.0mol% or less, and more preferably 88.7mol% or less, based on the total number of moles of the components constituting the silicate glass. In SiO₂When the content of (B) is more than 90.0mol%, the calcination temperature is preferably too high.

The silicate glass of the present invention contains Al as a constituent₂O₃。Al₂O₃The content of (b) is 4.0mol% or more, preferably 5.0mol% or more, and more preferably 5.7mol% or more based on the total number of moles of the components constituting the silicate glass. In Al₂O₃In the case where the content of (B) is less than 4.0mol%, it is suitable for the calcination temperature to be excessively loweredLow. Further, Al₂O₃The content of (b) is 15.0mol% or less, preferably 13.0mol% or less, and more preferably 12.7mol% or less, based on the total number of moles of the components constituting the silicate glass. In Al₂O₃When the content of (B) is more than 15.0mol%, the calcination temperature is preferably too high.

Further, as Al₂O₃When the silicate glass composition is expressed by a molar ratio, Al is contained₂O₃Relative to the number of moles of the basic component (RO + R)₂Ratio of the total amount of the moles of O { (Al)₂O₃Is given in mole number of (3)/(RO + R)₂Total mole number of O) } is required to be 0.70 or more, preferably 0.72 or more, and more preferably 0.85 or more, from the viewpoint of being suitable for the calcination temperature. The alkali component is a component constituting the silicate glass of the present invention and is represented by the general formula RO or R₂And O is a metal oxide. R of the metal oxide represented by RO represents a metal element of group 2 or group 12 of the periodic table, and examples of RO include ZnO, CaO, MgO, BaO, SrO, and the like. R₂R of the alkali metal oxide represented by O represents a metal element of group 1 of the periodic table, and R is₂O, for example, Li₂O、Na₂O、K₂O, and the like. Further, as Al₂O₃With the content of basic component (RO + R)₂Molar ratio of the content of O { (Al)₂O₃Is given in mole number of (3)/(RO + R)₂Total mole number of O) }, the upper limit value is not particularly limited, and may be 3.0 or less, 2.0 or less, 1.5 or less, or 1.3 or less. In another embodiment, when the metal oxide represented by RO constituting the silicate glass of the present invention is substantially CaO only, there is { (Al)₂O₃(iii) mol number of (C)/(CaO + Al)₂O₃+K₂O+Na₂Total mole number of O) } 0.70 or more.

In one embodiment, R is preferably R from the viewpoint of further having an excellent effect of suppressing a change in color tone of zirconia as a base material even when the silicate glass of the present invention is fired simultaneously with a zirconia green body₂The content (number of moles) of O is greater than the content (number of moles) of RO. Specifically, the silicate glass of the present invention preferably satisfies 1.0<{(R₂The number of moles of O)/(the number of moles of RO) }<300, more preferably satisfies 1.2<{(R₂The number of moles of O)/(the number of moles of RO) }<200, and more preferably satisfies 1.4<{(R₂The number of moles of O)/(the number of moles of RO) }<150。

The silicate glass of the present invention contains K as a constituent₂O。K₂The content of O is 1.0mol% or more, preferably 3.0mol% or more, and more preferably 3.6mol% or more based on the total number of moles of the components constituting the silicate glass. At K₂When the content of O is less than 1.0mol%, vitrification may be unstable. Furthermore, K₂The content of O is 10.0mol% or less, preferably 9.0mol% or less, and more preferably 8.3mol% or less, based on the total number of moles of the components constituting the silicate glass. At K₂When the O content is more than 10.0mol%, the thermal expansion coefficient is increased.

The silicate glass of the present invention contains Na as a constituent₂O。Na₂The content of O is 0.1mol% or more, preferably 1.0mol% or more, and more preferably 1.7mol% or more based on the total number of moles of the components constituting the silicate glass. In Na₂When the content of O is less than 0.1mol%, vitrification may be unstable. Further, Na₂The content of O is 7.0mol% or less, preferably 4.0mol% or less, and more preferably 3.8mol% or less, based on the total number of moles of the components constituting the silicate glass. In Na₂When the content of O is more than 7.0mol%, the thermal expansion coefficient is increased.

The silicate glass of the present invention contains CaO as a constituent component. The content of CaO is 0.01mol% or more, preferably 0.05mol% or more, and more preferably 0.1mol% or more with respect to the total number of moles of the components constituting the silicate glass. By containing 0.01mol% or more of CaO, CaO can function as a melting agent in the glass. The content of CaO is 15.0mol% or less, preferably 13.0mol% or less, and more preferably 12.2mol% or less, based on the total number of moles of the components constituting the silicate glass. Thus, a silicate glass having a preferable suitable firing temperature and thermal expansion coefficient can be obtained.

Further, the silicate glass of the present invention, even if calcined simultaneously with the zirconia green body, has a more excellent effect of suppressing the change in the color tone of the zirconia as the base material, and K is₂The O content (in moles) is preferably more than Na₂Content (number of moles) of O. Specifically, the silicate glass of the present invention preferably satisfies 1.0<{(K₂Mole number of O)/(Na₂The number of moles of O) }, more preferably 1.5<{(K₂Mole number of O)/(Na₂The number of moles of O) }, more preferably satisfies 2.0<{(K₂Mole number of O)/(Na₂The number of moles of O) }. { (K)₂Mole number of O)/(Na₂Mole number of O) } value, i.e., K₂O and Na₂The upper limit of the molar ratio of O is not particularly limited, and may be less than 100, less than 50, or less than 30.

The silicate glass of the present invention may further contain at least 1 selected from pigments and opacifiers (opalescents) in order to adjust the color, fluorescence, transmittance, and the like of the silicate glass and a sintered body obtained therefrom. At least 1 selected from the aforementioned pigments and opacifiers (opalescent agents) may or may not constitute the silicate glass of the present invention. As the pigment, an oxide of at least 1 element selected from, for example, P, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, Zr, Sn, Sb, Bi, Ce, Pr, Sm, Eu, Gd, Tb and Er can be used. Examples of such oxides include CoO, NiO, and Fe₂O₃、Cr₂O₃And the like. As the pigment, a fluorescent pigment may be used. As opacifying agents, use may be made, for example, of compounds selected from TiO₂、ZrO₂、ZrSiO₄、SnO₂And CeO₂At least 1 compound of (a). The pigment and the opacifying agent contained in the silicate glass may be 1 kind of compound or 2 or more kinds of compounds. The content of the pigment and the opacifying agent may be 0.001 to 3.0mol%, 0.01 to 1.0mol%, and 0.01 to 0.1mol% based on the total mole number of the components constituting the silicate glass.

The inventionIf the silicate glass contains B₂O₃It is suitable for the calcination temperature to be lowered, and therefore, B is substantially not contained₂O₃. In addition, in one embodiment, the silicate glass of the present invention may be substantially free of HfO₂. Further, in one embodiment, the silicate glass of the present invention may contain Li₂O, may be substantially free of Li₂And O. Silicate glass containing Li₂In the case of O, Li₂The content of O may be 0.1 to 5.0mol%, or 0.1 to 1.0mol%, based on the total number of moles of the components constituting the silicate glass. In one embodiment, the silicate glass of the present invention may contain MgO, or may not substantially contain MgO. When the silicate glass contains MgO, the content of MgO may be 0.1 to 9.0mol%, 0.3 to 8.0mol%, or 0.5 to 6.0mol% based on the total number of moles of the components constituting the silicate glass. In one embodiment, the silicate glass of the present invention may contain BaO, or may not substantially contain BaO. When the silicate glass contains BaO, the content of BaO may be 0.1 to 5.0mol%, 0.3 to 4.0mol%, or 0.5 to 2.0mol% with respect to the total number of moles of the components constituting the silicate glass. In one embodiment, the silicate glass of the present invention may contain SrO, or may not substantially contain SrO. When the silicate glass contains SrO, the SrO content may be 0.1 to 5.0mol%, 0.3 to 4.0mol%, or 0.5 to 2.0mol% based on the total number of moles of the components constituting the silicate glass. In one embodiment, the silicate glass of the present invention may contain ZnO, or may not substantially contain ZnO. When the silicate glass contains ZnO, the content of ZnO may be 0.1 to 5.0mol%, 0.3 to 4.0mol%, or 0.5 to 2.0mol% with respect to the total number of moles of the components constituting the silicate glass. In the present specification, "substantially free" means that the content of a certain component is less than 0.1mol%, preferably less than 0.05mol%, and more preferably less than 0.01mol% with respect to the total number of moles of components constituting the silicate glass.

The silicate glass of the present invention can be formed into a shape of, for example, powder. The average particle diameter (d50) of the powder is preferably 75 μm or less, more preferably 50 μm or less, and still more preferably 40 μm or less. The average particle diameter (d50) of the powder can be measured by a laser diffraction particle size distribution measuring apparatus (MT 3300EXII, manufactured by マイクロトラック and ベル Co.).

The suitable firing temperature of the silicate glass of the present invention is preferably 1100 ℃ or higher, more preferably 1200 ℃ or higher, and further preferably 1350 ℃ or higher. When the suitable calcination temperature is set to satisfy the above range, for example, in the case where silicate glass is used as a dental ceramic material and calcined simultaneously with the substrate, discoloration of the substrate can be suppressed. The suitable calcination temperature of the silicate glass in the present invention means a state where the surface is smooth and glossy, the transparency is high, and the background is transmitted when the molded body containing the silicate glass is heated and the temperature is raised, that is, the lowest temperature at which the silicate glass can be considered to be sufficiently calcined can be obtained. For example, if a powdery silicate glass is formed into a compact and heated to raise the temperature, the powders usually start to bond with each other at the initial stage of heating, and if the temperature is raised further to reach a temperature, the transparency of the surface of the compact is high and the background is transmitted, and this temperature becomes a suitable firing temperature. If the temperature of the molded article is further increased, the molded article is melted and the shape thereof is not maintained in many cases, and deformation such as integration due to surface tension starts to occur. The suitable calcination temperature can be determined by the method described in the examples below. The upper limit of the suitable calcination temperature is not particularly limited. Suitable calcination temperatures may be 1800 ℃ or lower.

The silicate glass of the present invention preferably has a thermal expansion coefficient of 11.0X 10^-6K-1The following, more preferably 10.5X 10^-6K-1The following, more preferably 10.0 × 10^-6K-1The following, particularly preferably 9.9X 10^-6K-1The following. When the thermal expansion coefficient is within the above range, when the silicate glass of the present invention is applied to a substrate as a dental ceramic material and heated, the occurrence of defects such as deformation and cracks can be more effectively suppressed. Specifically, the thermal expansion coefficient can be measured by the method described in the examples below.

The crystal system of the silicate glass of the present invention is not particularly limited, and may be cristobalite or amorphous. The method of measuring the crystal system can be confirmed by an X-ray diffraction (XRD) pattern as described in examples described later.

The silicate glass of the present invention can suppress the change in color tone of the zirconia sintered body as the base material even when the silicate glass is simultaneously calcined with the zirconia green body and simultaneously calcined at the zirconia calcination temperature. Color difference Δ Ea indicating change in hue of silicate glass of the present invention^*b^*Preferably 2.7 or less, more preferably 2.0 or less, and further preferably 1.6 or less. Color difference Δ Ea^*b^*The measurement method (2) is as described in examples.

Next, an example of the method for producing a silicate glass of the present invention will be described.

First, raw materials such as oxides corresponding to the respective components constituting the target silicate glass are prepared. Next, these raw materials were dried, weighed according to the composition, and mixed to obtain a mixture. Subsequently, the mixture is melted at a high temperature to obtain a melt, and the melt is cooled to produce cullet. The melting temperature is not particularly limited, and may be 1300 ℃ or higher, and may be 1400 ℃ or higher. Thereafter, the obtained cullet is pulverized to a predetermined particle size range, and if necessary, sieved, whereby a powdery silicate glass can be obtained.

The silicate glass obtained in the above manner can be used as it is for a dental ceramic material or the like described later. Alternatively, as described above, in order to adjust the color, fluorescence, transmittance, etc. of the silicate glass and the sintered body obtained therefrom, at least 1 component selected from the group consisting of a pigment and an opacifying agent is added to the obtained silicate glass, and the obtained mixture is sieved as necessary so as to achieve a predetermined particle size range, thereby producing a silicate glass containing at least 1 component selected from the group consisting of a pigment and an opacifying agent.

The silicate glass of the present invention can be used for dental purposes, and in particular, can be suitably used as a dental ceramic material. The dental ceramic material may be substantially composed of only silicate glass. In the dental ceramic material substantially consisting of only the silicate glass, the content of components other than the silicate glass contained in the dental ceramic material is preferably less than 10% by mass, more preferably less than 5% by mass, and still more preferably less than 1% by mass.

In another embodiment of the present invention, there is provided a composite comprising the silicate glass and a substrate, wherein the substrate comprises a ceramic. In another embodiment, the composite is obtained by firing a sintered body. Further, as another embodiment, there is a dental product including the sintered body. The material of the substrate is not particularly limited as long as it is a ceramic that can be used for dental applications, and is preferably a zirconia ceramic (as ZrO), since the effects of the present invention and the like are more remarkably achieved₂Ceramics as a main component (the most abundant component). When the silicate glass of the present invention is used as a dental ceramic material, the sintered body of the silicate glass of the present invention preferably has a thermal expansion coefficient in a range close to that of the base material. For example, when the silicate glass of the present invention is used as a dental ceramic material, the difference between the thermal expansion coefficient of the substrate such as zirconia ceramic as the substrate and the thermal expansion coefficient of the silicate glass as the dental ceramic material is preferably 5.0 × 10^-6K-1The following.

In another embodiment of the present invention, there is provided a method for using the silicate glass, which comprises the step of coating or setting the dental ceramic material containing the silicate glass of the present invention on a substrate, wherein the substrate is a ceramic. In the use method, the substrate is preferably zirconia ceramic.

Further, as another embodiment of the present invention, namely a method for producing a sintered body (a composite body of the sintered body containing the silicate glass of the present invention and a substrate containing a ceramic), there is a method for producing a sintered body, which comprises a step of coating or setting a dental ceramic material containing the silicate glass on the substrate, and a step of simultaneously calcining the substrate and the dental ceramic material. In the above production method, the substrate is preferably a zirconia ceramic core. The silicate glass of the present invention can also be used in a manufacturing method including the steps of coating or building a dental ceramic material containing the silicate glass of the present invention on a fired ceramic-containing substrate, and firing the dental ceramic material.

The present invention includes embodiments in which the above-described configurations are combined in various ways within the scope of the technical idea of the present invention, and the upper limit value and the lower limit value of the numerical range (the content of each component, the value calculated from each component, each physical property, and the like) may be appropriately combined as long as the effects of the present invention are achieved.

Examples

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples at all, and various modifications can be made by those having ordinary knowledge in the art within the scope of the technical idea of the present invention.

Examples 1 to 4 and comparative examples 1 to 2

Silicate glass and a sintered body obtained by calcining the same were prepared, and various physical properties were measured by the methods described below. First, the oxides listed in table 1 for forming the components constituting the silicate glass were heated and dried at 120 ℃. Next, the respective oxides were weighed so as to be described in table 1, and mixed by a ball mill to obtain a mixture.

[ Table 1]

Content of each constituent component

*2 Al₂O₃Relative to the number of moles of the basic component (RO + R)₂O) total moles of the total.

Next, the mixture was filled in a melting crucible 22557and melted at 1500 ℃ in the atmosphere. After cooling the melt, the glass was cullet-ground, and the resulting cullet was further ground using a ball mill. The resultant pulverized material was sieved through a #200 mesh sieve. In this manner, a powdery silicate glass was produced and used for each measurement described later. The mesh size of the screen is in accordance with the nominal mesh size W of JIS Z8801-1-2006.

[ examples 5 to 6]

First, the oxides listed in table 1 for forming the components constituting the silicate glass were heated and dried at 120 ℃. Next, the respective oxides were weighed in the same manner as in example 1 in example 5 and in the same manner as in example 4 in example 6, and mixed by a ball mill to obtain a mixture.

Next, the mixture was filled in a melting crucible 22557and melted at 1500 ℃ in the atmosphere. After cooling the melt, the glass was cullet-ground, and the resulting cullet was further ground using a ball mill. The resultant pulverized material was sieved through a #200 mesh sieve. Thus, a powdery silicate glass was produced, and 3.0mol% of NiO was added to example 5 and 0.01mol% of TiO was added to example 6 as a pigment and an opacifying agent in the following proportions based on 100mol% of the silicate glass₂And used for each measurement described later. The mesh size of the sieve is a nominal mesh size W according to JIS Z8801-1-2006.

[ method for determining suitable calcination temperature ]

The powdery silicate glass obtained by the above method was mixed in purified water to form a slurry, and then filled in a cylindrical mold having a diameter of 16mm × 1.6mm, and condensation (moisture removal) and water absorption were repeated to obtain a silicate glass molded body. Next, the molded article was calcined in a porcelain calciner (trade name: ノリタケカタナ (registered trademark) F-1 ", manufactured by SK メディカル electronic Co., Ltd.) for a dental technician, and the molded article was placed in a kiln at room temperature, heated to an arbitrary specific temperature, and calcined. Thereafter, the mixture was left to cool immediately, and after left to cool to room temperature, the calcined state was visually observed. When the surface of the molded body (sintered body) after the treatment is in a smooth and glossy state, has high transparency, and has a background transmitted therethrough (i.e., in a state of being calcined), and a sintered body in a state of maintaining the shape before the calcination (i.e., in a state of not being deformed by excessive calcination) is obtained, the lowest temperature at which the sintered body in such a state is obtained is set to the suitable calcination temperature of the silicate glass in the present invention. The evaluation results of the examples and comparative examples are shown in table 2.

[ method of confirming crystal system ]

In XRD diffraction analysis of the powdery silicate glass obtained by the above method, measurement is performed with the measurement angle 2 θ set in the range of 0 ° to 60 ° by an XRD analyzer (trade name: RINT-TTR III, manufactured by リガク) using CuK α radiation as a radiation source.

[ method for measuring thermal expansion coefficient ]

Thermal expansion coefficient the sintered body obtained by calcining a silicate glass was used for the test pieces in accordance with ISO 6872: 2015. Specifically, the measurement was carried out by the following method.

The powdery silicate glass obtained by the above method is mixed in purified water to form a slurry. Thereafter, the slurry obtained was filled in a cylindrical silicon frame having a diameter of 7mm × 24mm, and the condensation and water absorption were repeated to obtain a molded article. Next, the molded article was calcined in a porcelain calciner (trade name: "ノリタケカタナ (registered trademark) F-1", manufactured by SK メディカル electronic Co., Ltd.) for a dental technician, the molded article was placed in a kiln at room temperature, and the fired article was heated to a suitable calcination temperature shown in Table 2. Thereafter, the mixture was left to cool immediately and left to cool to room temperature to obtain a sintered body. Next, the sintered body was adjusted to a diameter of 5mm by 20mm by using a grinder (hand-operated grindstone) to obtain a test piece. Next, the test piece was heated from 24 ℃ or lower to 550 ℃ at 5 ℃ per minute using a thermomechanical analyzer (trade name: Thermo plus TMA8310, manufactured by Kokai Co., Ltd., リガク), and the thermal expansion coefficient up to 25 to 500 ℃ was measured. The evaluation results of the examples and comparative examples are shown in table 2.

[ color difference (. DELTA.Ea)^*b^*) Method of measurement of]

First, a commercially available zirconia disk (trade name: "ノリタケカタナ (registered trade name) ジルコニア", manufactured by disk HT-12, クラレノリタケデジタル K.) was cut out using a diamond cutter, and a flat zirconia frame of 10 mm. times.10 mm. times.2 mm was prepared. Next, the resultant was heated from room temperature to 1500 ℃ with a porcelain calciner (trade name: "ノリタケカタナ (registered trademark) F-1", manufactured by SK メディカル electronic Co., Ltd.) for dental technicians, and calcined. After the calcination, the surface was polished under running water to a thickness of 1.50mm using a polishing paper of diamond abrasive grains, and the surface was made matte by blasting alumina sand having a particle size of 0.05mm at 0.2 MPa. And finally, putting the zirconium oxide frame into acetone, and carrying out ultrasonic washing to obtain the zirconium oxide frame.

Next, sample 1, in which a ceramic material layer reproducing the enamel color of the natural tooth was formed, was prepared on the zirconia frame. Specifically, as the ceramic material, each powdery silicate glass shown in table 1 was used, and 2-phenoxyethanol as a solvent was used, in terms of the mass of the ceramic material: solvent mass = 67: the ratio of 33 is sufficiently blended. The resulting slurry containing the ceramic material was coated on the surface of the zirconia frame, heated to 1500 ℃, and calcined. Subsequently, the ceramic material layer was polished to a thickness of 0.03 mm. Thus, sample 1 was produced.

Further, a commercially available zirconia disk (trade name: カタナジルコニア (registered trade name) ジルコニア, manufactured by Kogyo K.K. HT-12, クラレノリタケデジタル, thermal expansion coefficient: 9.9X 10^-6K-1) A flat zirconia frame of 10 mm. times.10 mm. times.2 mm was cut out by a diamond cutter. Next, sample 2, in which a ceramic material layer reproducing the enamel color of natural teeth was formed, was prepared on the zirconia frame of the unsintered body. Specifically, as the ceramic material, the substances shown in table 1 were used, and 2-phenoxyethanol as a solvent was used, in terms of the mass of the ceramic material: solvent mass = 67: the ratio of 33 is sufficiently blended. The resulting ceramic material-containing slurry was coated on the surface of the frame and heated to 1500 ℃ to simultaneously calcine the zirconia frame and the ceramic material. Then, the zirconia frame is used as a thickness of 1.50mm, and the ceramic material layer reaches a thickness of 0.03mAnd m is used for grinding. Thus, sample 2 was produced.

For samples 1 and 2 thus prepared, a dental color measuring instrument (クリスタルアイタイプ CE100-DC, オリンパス co., ltd.) was used, and the color measurement was performed in accordance with JIS Z8781-4: 2013, to L^*a^*b^*Chroma (color space) colorimetry in the table color system. The color of sample 1 was designated as (L)^*1,a^*1,b^*1) The color of sample 2 is denoted as (L)^*2,a^*2,b^*2) As (L) of^*1,a^*1,b^*1) And (L)^*2,a^*2,b^*2) The following Δ Ea was calculated^*b^*。

ΔEa^*b^*=[(ΔL^*)²+(Δa^*)²+(Δb^*)²]^1/2

ΔEa^*b^*Is a difference in the production method, namely, an index of change in color tone (discoloration) of the zirconia base material,. DELTA.Ea^*b^*Greater the color change, Δ Ea^*b^*Smaller is less discoloration. Delta Ea^*b^*From ISO/TR 28642: 2011 is preferably 2.7 or less. Further, Δ Ea^*b^*More preferably 2.0 or less, and still more preferably 1.6 or less. The evaluation results of the examples and comparative examples are shown in table 2.

[ Table 2]

。

The silicate glass of comparative example 1 is suitably calcined at 800 ℃ and is amorphous. The color difference in comparative example 1 was larger than that in examples 1 to 6, as described above. Further, comparative example 2 was suitable in that the calcination temperature was 1000 ℃ and it was amorphous. The color difference in comparative example 2 is also larger than the color differences in examples 1 to 6 as described above. For example, in the case of simultaneous firing with zirconia, since silicate glass is fired on a zirconia substrate, it is preferable that the suitable firing temperature of silicate glass is high so that defects do not occur in the substrate and discoloration does not occur. As shown in table 2, the silicate glasses according to examples 1 to 6 have a higher firing temperature than the silicate glass according to comparative example 2, and the color difference between sample 1 and sample 2 is very small. Therefore, the silicate glass of the present invention is suitable for a dental ceramic material which is calcined simultaneously with zirconia, for example.

The silicate glass, the sintered body, the dental product, the method for using the dental product, and the method for producing the dental product according to the present invention are described based on the above embodiments, but are not limited to the above embodiments, and various modifications, alterations, and improvements may be made to various disclosed elements (including the elements of the claims, the elements of the embodiments, the examples, and the like) within the scope of the entire disclosure of the present invention and based on the basic technical idea of the present invention. In addition, various combinations, substitutions, and selections of various disclosed elements (including elements of the claims, elements of the embodiments, examples, and the like) may be made within the scope of the entire disclosure of the present invention.

Industrial applicability

Since the silicate glass of the present invention has a composition of specific components and is suitable for a high firing temperature, discoloration of the substrate can be avoided even in firing simultaneously with the ceramic of the substrate. Therefore, the silicate glass of the present invention is advantageous in that the steps are simple and the production time can be shortened as much as possible when producing a dental product.

Claims

1. A silicate glass comprising:

65.0 to 90.0mol% SiO₂、

4.0 to 15.0mol% of Al₂O₃、

1.0 to 10.0mol% of K₂O、

0.1 to 7.0mol% of Na₂O, and

0.01 to 15.0mol% of CaO,

substantially free of B₂O₃，

{(Al₂O₃Is given in mole number of (3)/(RO + R)₂Total mole number of O) } is 0.70 or more, R of the metal oxide represented by RO represents a metal element of group 2 or group 12 of the periodic table, R represents₂R of the metal oxide represented by O represents a metal element of group 1 of the periodic table.

2. The silicate glass of claim 1, comprising:

69.0 to 89.0mol% SiO₂、

5.0 to 13.0mol% of Al₂O₃、

3.0 to 9.0mol% of K₂O、

1.0 to 4.0mol% of Na₂O, and

0.05 to 13.0mol% of CaO,

substantially free of B₂O₃，

3. The silicate glass according to claim 1 or 2, which is substantially free of ZnO.

4. The silicate glass according to any one of claims 1-3, which is substantially free of MgO, BaO, and SrO.

5. The silicate glass according to any one of claims 1 to 4, wherein the suitable calcination temperature is 1100 ℃ or higher.

6. The silicate glass according to any one of claims 1-5, wherein the glass is a glass according to ISO 6872: 2015 to a thermal expansion coefficient of 11.0X 10^-6K-1The following.

7. The silicate glass according to any one of claims 1 to 6, further comprising at least 1 selected from a pigment and an opacifying agent.

8. A composite comprising the silicate glass according to any one of claims 1 to 7 and a substrate comprising a ceramic.

9. The composite of claim 8, wherein the ceramic is a zirconia ceramic.

10. A sintered body of the composite body according to claim 8 or 9.

11. A dental product comprising the sintered body of claim 10.